High doses of fish oil for coronary heart disease need doctors' supervision
29 November 2002
The American Heart Association (AHA) has recommended that doctors supervise omega-3 fatty acid supplementation in people with coronary heart disease (CHD).
The AHA recommends that people with documented CHD should eat about 1 g of omega-3 fatty acids a day, preferably from oily fish.
If a patient cannot obtain this from the diet, supplements may be necessary — taken after consultation with a doctor.
Doctors are also advised to supervise patients taking omega-3 fatty acids to lower triglycerides. The AHA recommends 2 to 4 g a day in capsule form. Triglycerides are a type of fat found in the bloodstream along with cholesterol — and just like cholesterol, too much can cause disease of the blood vessels.
The AHA's scientific statement 'Fish Consumption, Fish Oil, Omega-3 Fatty Acids and Cardiovascular Disease' recommends people without CHD eat a variety of fish — preferably oily fish — at least twice a week.
It also recommends eating oils and foods rich in alpha-linolenic acid — such as canola, linseed and soybean oils, or walnuts (Circulation 2002; 106; 2747-57).
A fishy aftertaste is the most common side effect from omega-3 fatty acid supplementation, with the most marked effect reported in people who take more than 3 g a day.
Other side effects with high dose supplements include a likely rise in low-density lipoprotein cholesterol — the so-called 'bad' cholesterol — usually only in people with raised triglycerides, gastrointestinal disturbances (moderate risk), worsening blood glucose elevation (moderate risk, usually only in people with impaired glucose tolerance or diabetes) and clinical bleeding (low risk).
There are also side effects with lower daily doses, but the risk is generally smaller with 1 to 3 g a day, and smaller still with doses less than 1 g a day.
Last Reviewed: 02 December 2002
- 1. Medical Observer Weekly 29/11/02
